Vulnerability identifier: #VU9125

Vulnerability risk: Low

CVSSv3.1: 7.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2017-12319

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XE
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description
The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft. A remote attacker can send a specially crafted BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet, corrupt the BGP routing table and cause the device to reload.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Update to version 16.3 or later.

Vulnerable software versions

Cisco IOS XE: 15.5.3 S4.1 - 16.2.1.25

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171103-bgp

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.